Yes, cables remain very important with both SS and Tubes. With tubes though, alot of the annoyances involved with HiFi seem to disappear or at least diminish. Things like only sounding good at 3:00 in the morning, or when the fridge is off. Or sounding bad for days after vacuuming (I'm not kidding)or when computers are running. Tubes can sound so right and likable that these problems vanish or become unimportant. I suspect cables may be less of a "Life or death" decision for good sound with Tubes, but you will still need to tune the system with the proper sympathetic cable choices till you get it just right. Possibly not the same choices that worked with your SS system, but I wouldn't dump your cables till you at least try them with a new setup.